Inflatable Structure design, development and testing for the EFESTO project Earth-application heat shield

The European Union H2020 EFESTO project coordinated by DEIMOS aims at advancing the TRL of hypersonic Inflatable Aerodynamic Decelerators (HIAD) for re-entry vehicles, paving the way for a future IOD mission. The EFESTO project has identified two key applications to drive and consolidate the design of HIAD systems: a Martian entry mission and a rocket stage recovery in Earth’s atmosphere. In particular, the Earth case targets the recovery of the VEGA AVUM upper stage. This EDL mission consists of a deorbiting from Polar Orbit, followed by a controlled entry phase that exploits the deceleration provided by a 4.8m diameter class HIAD. This paper focuses on the effort carried out in designing the EFESTO Inflatable Structure for the Earth application scenario and in developing and testing the Ground Demonstrator at a meaningful scale. The engineering excursus, starting from the EFESTO system-level requirements to the Inflatable Structure subsystem detailed design, is described and detailed. The process was mainly supported by technology-driven and system considerations, structural/mechanical modelling, simulations and analysis. Architectures identification and trade-off, interface engineering, budget definition, and technology-related design aspects will also be presented. The design, manufacturing and testing of a 1:2-scale Ground Demonstrator of the Inflatable Structure will be provided and the related technical achievements analyzed. The EFESTO achievements presented in this paper prove that HIAD systems can allow re-entry and exploration missions favouring payloads maximization both with respect to mass and volume. Nonetheless, the paper also aims to remark the need to foster further effort in the field of HIAD, to increase the TRL of that kind of technology and prepare it for operational missions in the near future. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 821801. More information is available at: http://www.efesto-project.eu